Use of Injection Drugs and Any Form of Methamphetamine in the Portland, OR Metro Area as a Driver of an HIV Time-Space Cluster: Clackamas, Multnomah, and Washington Counties, 2018-2020.

We describe the response to detection of a time-space cluster of new HIV infection in the Portland, OR metro area among people who inject drugs (PWID) and/or people who use any form of methamphetamine. This time-space cluster took place in a region with a syndemic of homelessness and drug use. The investigation included new HIV diagnoses in 2018, 2019, and 2020 in Clackamas, Multnomah, and Washington Counties. Public health response included activating incident command, development and implementation of an enhanced interview tool, outreach testing, and stakeholder engagement. We identified 396 new cases of HIV infection, 116 (29%) of which met the cluster definition. Most cluster cases had no molecular relationships to previous cases. Persons responding to the enhanced interview tool reported behaviors associated with HIV acquisition. Field outreach testing did not identify any new HIV cases but did identify hepatitis C and syphilis infections. We show the importance of a robust public health response to a time-space cluster of new HIV infections in an urban area.

Notes from the Field: Shigellosis Outbreak Among Men Who Have Sex with Men and Homeless Persons - Oregon, 2015-2016.

In July 2015, Shigella sonnei infections with a specific pulsed-field gel electrophoresis (PFGE) pattern linked to a multistate outbreak were recognized among men who have sex with men (MSM) in the Portland metropolitan area, and an outbreak investigation was initiated. During November 2015, isolates with PFGE patterns indistinguishable from the outbreak strain were identified in cases reported in four women, none of whom had epidemiologic links to other affected persons; however, three reported homelessness. In the ensuing months, additional S. sonnei infections were reported among homeless persons in the Portland area.